Waterproof motorized surfboard



July 22, 1969 c, SMITH 3,456,613

WATERPROOF MOTORIZED SURFBOARD Filed Jan. 24, 1968 /4 I I 1 F/G. 5

INVENTOR ROBERT C. SMITH EG' 4 BY Emmi? United States Patent "ice 3,456,613 WATERPROOF MOTORIZED SURFBOARD Robert C. Smith, Oakwood Manor, Moorhead, Minn. 56560 Filed Jan. 24, 1968, Ser. No. 700,183 Int. Cl. 1363b 35/ 72; B63h /00 US. Cl. 11570 4 Claims ABSTRACT OF THE DISCLOSURE The present invention resides in an elongated float provided with a cockpit capable of holding a storage battery. A submersible electric motor is mounted upon the outer surface of the surfboard rearwardly of the cockpit, and is provided with a driving propeller. A control cord issues from the top panel of the surfboard near the forward end thereof and is provided with a control switch. Actuation of the switch acts through a relay to energize the motor and to keep the motor in operation as long as the switch is closed.

This invention relates to an improvement in waterproofing motorized surfboard and deals particularly with a surfboard powered by a waterproof electric motor supported on the exterior under surface of the surfboard.

In my previous application for patent, Ser. No. 598,326 filed Dec. 1, 1966, now Patent No. 3,405,677 I disclose a surfboard having a cockpit which extended downwardly into a longitudinal fin, and which included a source of electrical power and an electric motor. The electric motor included a shaft which extended through the rear of the fin and supported a propeller designed to drive the surfboard. This structure has been successfully made and used and has been proven generally successful. However, difliculty was experienced in the event the operator did not effectively seal the cockpit during use, or left the cockpit open during the battery recharging operation. If water entered the cockpit, it had a tendency to burn out the motor, resulting in a considerable replacement expense.

'I have found that most of the previous difficulty can be eliminated by providing a motor of the submersible type which can be mounted on the exterior surface of the surfboard. This arrangement not only eliminates the danger of burning out the electric motor, but also eliminates the friction seal which was previously necessary to prevent liquid from entering the cockpit about the propeller shaft. With this arrangement, much of the previous difficulty has been eliminated.

A feature of the present invention resides in a motorized surfboard which requires a cockpit of only suflicient size to accommodate the battery and operating relay. As a result, the size of the cockpit may be greatly reduced, and the cost of production may be correspondingly decreased.

A further feature of the present invention resides in the provision of a motorized surfboard in which the cockpit does not necessarily have to be sealed with a watertight seal. While it is obviously preferable to maintain the cockpit free of water, water entering the cockpit may affect only the battery and the relay, both of which are normally enclosed in a waterproof case. Thus carelessness on the part of the user in permitting water to enter the cockpit will not have any serious effect upon the device or upon the operation thereof.

A further feature of the present invention resides in the provision of a battery-driven motor which is controlled by a relay, the relay being controlled by a manually operable switch connected on the end of a cord designed to be held in the hand of the surfboard operator. As long as the switch is held in closed position, the motor Patented July 22, 1969 will continue to operate. However, in the event the operator falls or jumps from the surfboard, the motor will stop and remain stopped till the switch is again manually operated.

These and other objects and novel features of the pres ent invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

FIGURE 1 is a perspective view of the surfboard in readiness for use.

FIGURE 2 is a bottom plan View of the surfboard illustrated in FIGURE 1 of the drawings.

FIGURE 3 is a vertical sectional view taken longitudinally through the mid-section of the surfboard, showing the relative arrangement of the motor, relay and battery.

FIGURE 4 is a transverse sectional view through the surfboard near the rear end thereof, the view looking forwardly.

FIGURE 5 is a diagrammatic view of the wiring of the device.

The surfboard is indicated in general by the letter A. The surfboard A preferably includes an outer shell of fiberglass or other durable plastic material which is usually formed with an upper section 10 and a lower section 11. As is indicated in FIGURE 4 of the drawings, the upper section 10 includes a generally flat top panel 12 provided with downwardly projecting sides 13 which terminate in offset lips 14 which are offset a distance substantially equal to the thickness of the material to form an overlapping joint with the bottom section 11. The top panel 10 usually includes a transversely extending rear wall 15 and tapered forward portion 16 which tapers to a rounded point 17. The rear wall 15, as well as the tapered front wall portions 16 and rounded forward point 17 are formed similarly to the side wall 13 and the offset lip 14 terminates on a substantially common plane and extends about the entire periphery of the depending walls of the top section 10.

The bottom section 11 includes a bottom wall 19 which is substantially the same outline shape as the top panel 12, and this bottom wall 19 is provided with upwardly extending peripheral walls or flanges 20 which overlap the offset lips 14 of the top section 10 and are secured thereto with a waterproof seam. Thus the two sections are sealed together to provide a waterproof seam. Thus the two sections are sealed together to provide a hollow interior.

As indicated in FIGURE 2 of the drawings, the bottom panel 19 is interrupted by a downwardly projecting keel 21. including parallel downwardly extending sides 22 connected at their lower end by a transverse connection portion 23. The forward end 24 of the keel 21 tapers toward a rounded point, while the rear end 25 of the keel may be transversely of the length of the surfboard. As is indicated in FIGURE 3 of the drawings, the keel is hollow and forms a cockpit within the surfboard body. An aperture 26 is provided in the top panel 12'above the cockpit 23 encircled by offset inwardly extending flanges 27. A cover plate 29 rests upon the flanges 27 and is secured in place by bolts 30 or other detachable fastening means.

A bulkhead wall 38 extends across the body forwardly of the opening 26, and overlapping bulkhead wall flanges 28 extend across the body rearwardly of the opening 26. Bulkhead wall flanges similar to the flanges 28 may also be provided on opposite sides of the keel which forms the cockpit.

As is indicated in FIGURE 2, a short stabilizing keel 31 may also be provided extending along the longitudinal center of the bottom panel 19 at the rear end 15 of the body. In the arrangement illustrated, the keel 31 is tapered from a relatively narrow and shallow forward end 32 to a relatively wider and deeper rear end portion 33.

A water proof electric motor 34 is suspended below the bottom panel 19 rearwardly of the cockpit-forming keel 21. In the arrangement illustrated, the motor 34 is provided with a sleeve 35 projecting upwardly therefrom and which is internally threaded to accommodate the externally threaded sleeve 36 of an anchoring flange 37 secured to the bottom panel 19. The motor 34 is provided with a rearwardly extending drive shaft 39 which supports a propeller 40, the propeller being used to drive the surfboard.

The interior of the surfboard body between the two proof cable 44 extends forwardly from the cockpit to extend through the transverse center of the top panel 12 provided with a waterproof seal 45. The cable 44 extends from the top panel near the forward end thereof, and is of sufficient length to be held in the hand of the user of the surfboard. A waterproof switch 46 is provided on the end of the table 45.

FIGURE 5 diagrammatically illustrates the wiring diagram for controlling the surfboard. One terminal of the battery 42 is connected by a conductor 47 to one terminal 4 stop and the surfboard quickly loses its forward momenturn.

I claim:

1. A motorized surfboard including:

an elongated buoyant body,

a downwardly extending keel on the undersurface of said body and extending longitudinally thereof,

a hollow cockpit within said body, and extending into said keel,

a storage battery enclosed within said cockpit,

a submersible electric motor suspended beneath said body and rearwardly of said keel and aligned therewith, said motor including a longitudinally extending drive shaft,

a propeller on said drive shaft, and

manually. controlled means connecting said motor and said battery for energizing said motor.

2. The structure of claim 1 and in which said motor includes a mounting sleeve,

a flanged sleeve on the under side of said buoyant body in telescoping sealed relation to said mounting sleeve, and

conductors extending through said sleeves to said motor.

3. The structure of claim 1 and in which said manually controlled means includes a conductor cable including a pair of conductors extending from said buoyant body near the forward end thereof and of sufiicient length=to reach' to a point near the rear end of said body,

of the switch 46, the other terminal of which is connected T by a conductor 49 to the relay coil 50 of a relay 51. The other terminal of the relay coil 50 is connected to the second battery terminal by the conductor 52.

One terminal of the battery 42 is also connected by a conductor 53 to the relay armature 54 engageable with a fixed relay contact 55 upon energization of the coil 50. The relay contact 55 is connected by a conductor 56 to one terminal of the motor 34. The other terminal of the motor 34 is connected by conductor 57 to the second the circuit to the motor 34 energizing the motor. The

motor remains in operation as lOng as the switch 46 is manually held closed, and opens the relay circuit as soon as the switch pressure is released.

As will be noted, as long as the occupant of the surfboard is standing in position upon the surfboard and is holding the switch 46 closed, the propeller will drive the surfboard in a forward direction. In the event the occupant loses his balance or jumps from the surfboard, the switch 46 is released, and the motor 34 comes to a a manually operable switch on the end of said cable for manually connecting said conductors,

a relay in said cockpit including a relay coil and a normally open relay switch,

a circuit including said battery, said manual switch and said relay coil for energizing said relay coil upon actuation of said manual switch,

a second circuit including said battery, said relay switch and said motor for operating said motor when said relay switch is closed.

A 4. The structure of claim 1 and in which said manually controlled means includes:

a manually operable normally open manual switch,

a relay including a relay coil and a normally open relay switch actuable by said coil,

a first circuit including said battery, said manual switch and said relay coil operable to energize said relay coil upon closing of said manual switch,

/ a second circuit including said battery, said relay switch and said motor operable to energize said motor upon closing of said relay switch. I

TllYGVE M. BLIX, Primary Examiner 

